Wireless communication services continue to require higher data rates and lower bit error rates to provide an acceptable quality of service level. It is well known that employing multiple transmit and receive antennas increases the capacity of wireless channels. Transmit and receive diversity schemes represent powerful techniques to combat and mitigate the destructive effects of multi-path fading. A layered architecture, such as Bell Labs Layered Space-Time (BLAST) architecture, may provide high spectral efficiencies at reasonable decoding complexity based on an interference reduction (e.g., nulling) and interference canceling.
A diagonally-layered space-time architecture known as diagonal BLAST or D-BLAST is one such approach. D-BLAST utilizes multi-element antenna arrays at both transmitter and receiver, and an elegant diagonally-layered coding structure in which code blocks are disposed across diagonals in space-time. This processing structure leads to advantageous theoretical Shannon capacities, for instance, that grow linearly with the number of antennas (assuming equal numbers of transmit and receive antennas) wherein these rates may approach 90 percent of Shannon capacity. However, the diagonal space-time approach suffers from certain implementation complexities that tend to make an implementation less practical. For additional information concerning the operation of BLAST and D-BLAST architectures see U.S. Pat. No. 6,097,771, titled “Wireless Communications System having a Layered Space-Time Architecture employing Multi-Element Antennas”, and U.S. Pat. No. 6,317,466, titled “Wireless Communications System having a Space-Time Architecture employing Multi-Element Antennas at both the Transmitter and Receiver,” which are herein incorporated by reference.
Currently, each antenna element typically uses a single channel code or no channel code, thereby lowering its flexibility. Additionally, detecting and decoding a burst transmission from multi-element antennas may require more detection depth capability to achieve a required quality of service level, due to interference or multi-path reflections, than presently available. In such cases, delivering the bit rate at a desired bit error rate may be difficult even causing a channel outage in some cases.
Accordingly, what is needed in the art is way to provide an enhanced formatting and decision depth capability for wireless communication systems and, preferably, for wireless communication systems subject to burst transmissions employing multi-element antennas.